It's relatively simple, and I think would work. Some time ago I learned of a program idea called a "fee-bate", a fee is charged on an undesirable good, and the resulting money is then paid to lower the cost of a desirable good.
For instance one idea to reduce CO2 emissions would be to implement a carbon fee-bate system where fuels with a high carbon content would have their price raised, while the greener fuels would have their price lowered. So in an ideal world the consumer would then follow the price signals of the marketplace and shift to greener fuels.
I realized however the reason SUVs are popular is they're cheap to produce and can fetch a premium price, creating a large profit margin for automobile manufacturers. Because of this profitability, those companies manipulate the population using their fears to believe that the SUV is the safer vehicle, not necessarily on the vehicles own intrinsic merits.
So to get rid of the SUV, implement a fee-bate system, but instead of giving the money to the consumers, award the collected money to the auto companies in another despicable case of corporate welfare.
If one structured the fee-bate system to be awarded using some scoring system based on safety record, efficiency, and greenness of fuels. If the the system was enough to make a small car more profitable for an auto manufacturer than an SUV, I suspect they could change the fashion to smaller cars.
Sick, twisted, and likely to work.